The purpose of this study is to assess whether the relationship between Type A behavior pattern and severity of angiographically assessed coronary atherosclerosis, observed in some U.S. populations, exists in a southern U.S. clinical population containing significant numbers of black patients. Research on the Type A-coronary disease relationship has been performed largely on white, middle- or upper-class populations, predominantly of urban residence, and the relevance of this relationship to black populations with different socio-economic and residential characteristics has not been defined. We will perform psychological and physiological assessments on a group of 400 black and white males undergoing coronary angiography. We will examine the association between Type A behavior and severity of atherosclerosis, using multivariate analytic methods to control for the effects of biological risk factors. This cross-sectional study will assess, for the first time, whether the previously observed association between Type A behavior and severity of coronary atherosclerosis applies to black as well as to white men. This study will provide information on the relevance of the Type A construct to coronary disease in black men and on the social and phychological correlates of Type A behavior in black men.